Most of critical city (and corporate) infrastructure relies on concrete, cement, etc., yet this infrastructure is aging and fragile, and thus a potential threat to both economy and life. Any structure using concrete is subject to material failure, such as buildings, bridges, etc. This is an issue regardless of the cause: earthquake, fire, overload, impact, chemical attack (intentional or unintentional), etc., or simply just due to age. Given the opaque nature of concrete, evaluating the structural soundness of the concrete, or assessing for possible damage, is an expensive, complex, time-consuming effort, yet is required more and more due to the aging of critical infrastructure.